BEARFOOT DYNA RED

[hotguit]

Hi
 used the layout from this great site
I built mine with 470 n and 50K linear trebble pot but i have poor bass.
The pedal works fine but bass do not come out
Why?
Thank you
hotguit

[Jopn]

Have you tried it with just the 100n instead?  The 470n is supposed to boost the mids, which may make the bass less apparent.  

[hotguit]

No, never tried
I'll give it a try. So, 100 n instead of 470n right?
thank you
hot

[hotguit]

What is the res/cap combo or network that controls bass?
hot

[Frank_NH]

I'm assuming this is the circuit you're building (below).

Dyna Red is basically a RAT with clipping in the IC feedback loop via LEDs and hard clipping post IC.  What controls bass in the IC gain stage is the 1K resistor / 470 nF cap to ground.  Note that the vero layout here uses 100 nF for this cap.  As it stands with 100 nF, it is enhancing and (if necessary clipping) signals over 1592 Hz.  If you increase this to 470 nF, you enhance/clip signals over 339 Hz.  If you want to enhance/clip lower frequencies than that, try 1 uF.  But remember that there is clipping going on so the nature of the distortion will change.

The BJF version has a different network to control op amp clipping frequencies.  You can check out that vero layout to see how it's done.  I just built the BJF version and don't hear any lack of bass per se.  The tone (Treble) knob is not too effective, and could possibly use some redesign to give it better sweep.  However, the main thing I'm noticing with my Dyna Red is a slightly spitty diode decay, most likely due to the twin 1n4001s hard clipping to ground.  I am going to try some LEDs there to see if it improves things.  Between this and the Crunch Box, I like the Crunch Box better - but maybe some redesign of the Dyna Red will change my mind.

[hotguit]

As i socketed that cap (100 n to ground) now i'm just using a 470 n there; with 100 n the tone is too harsh.
Even with the 470n the pedal seems very poor in bass freq. (compared to the tone heard on you tube from the original pedal); i can not turn the trebble pot over 1 or too much highs come in (it is a LINEAR 50K pot)
Maybe with a LOG pot things change...
hot

[Frank_NH]

Do you have an audio probe?  If not, make one.  Then use it "listen" to the circuit at key points.  I'd be interested in what you hear:

(1) just after the op amp output (before the clipping diodes)
(2) after the clipping diodes and before the tone control
(3) after the tone control

I bet if you probe the circuit, you will find the spot where the bass frequencies are disappearing.  In fact, check the signal right before the op amp - is something strange happening there?

And, as always, check all of your components and make sure the resistor and capacitor values are what they should be (use the schematic as a reference for this).

Good luck!  

[Frank_NH]

Tonight I did some experimenting with my BJF Dyna Red and found that it sounds much better (to me) without the 1N4001 diodes hard clipping.  So I may put those diodes on a switch or change them out to LEDs.  Lots of options there.

It also occurred to me that you could put in a bass cut control just like the Timmy.  I won't do that for my build, but you could redesign the layout to accommodate it.

Edit:  I also removed the 22 nF cap to ground after the treble control.  Now it sounds perfect!  No hard clipping diodes and slightly brighter without the 22 nF cap, and the tone control has a better sweep (though still more subtle which is OK).  So I'll call this the Dyna Red Overdrive (DRO) - simple, basic, but good-sounding high gain overdrive!  

[hotguit]

Thank you
i will try and let you know
hot

[Frank_NH]

I should note that my mods don't address your concerns about lack of bass.  As I mentioned above, you can replace the 470 nF/1K leg in the op amp feedback network with the Timmy bass control:



This would require some modding of the vero but should be doable.

[hotguit]

With a log tone pot this pedal works really better; much more usable tone escursion.
A must to do
Thank you
hot